Specs for the Bill Lawrence L-500

[kevinT]

Does anyone have specs for this pickup? Can't seem to find any anywhere.

[eggman6]

You'll have a hard time cloning them without taking one apart since they dont use stanard bobbins, and the shape and size of these pickups obviously contributes alot, i think theres a chance the blades are actually the magnets aswell, although i could be wrong since i've never opened one up.

His L450 (now L600) humbuckers used polepeice magnets and it has been said similar sounds to the L500 can be achieved with them.

here are some of the specs

Clean = 2.8 Henry
Rhythm = 4.8 Henry
Lead = 6.8 Henry
XL (extra lead?) = 9.2 Henry

Total Depth (incl. rails/pole pieces): ~0.85"/~21.5mm

Bill Lawrence L-500/L-510/L-6xx humbucker = 1.350"/~34mm Width x 2.80"/~71mm Length
(~3.35"/~85mm long inclusive of the screw tags)

Cant seem to find the resistence right now, but an ebay seller claims the reading got from an L-500 lead to be 14.97k which sounds about right. Although at one point this changed (lowered i think by a few 100 ohm) to compensate for different magnets used, when alnico was used instead of ceramic due to availability.

you should be able to find out more here

http://guitarsbyfender.yuku.com/forum/view/id/11

[David Schwab]

I have an L-500. The regular L-500 reads 7.64K. The notes I have say 5000 turns of either 42 or 42.5 wire. A few aspects of the pickups are the narrower coils, thin stainless steel blades, and a big honkin' ceramic magnet! The aluminum plated plastic cover is supposed to affect the tone also.

The L-500XL is the hot one.

You can look up the patent on the pickup: 4364295

I also had a closed cover Lawrence pickup I got when I worked at American Showster. We used to get prototypes all the time. I never saw this pickup in production. It looked like an EMG. It was passive and had the cleanest brightest tone I've ever heard on a humbucker. The top end was very glassy.

I had it in one of my guitars for years, and then one coil went dead. Later I chipped off the case and all the polyester resin. it had the same bobbins as the L-500, slightly thinner blades and the same big magnet.

Here's some photos of an L-500 clone I picked up somewhere years ago. I looks like they made exact copies of Lawrence's bobbins and stuff, but they didn't include the solder terminals on the bobbins, or the PC board under the magnet. It even has screw holes in the cover that they didn't use. It sounds pretty much like the real thing.

[eggman6]

L-500 C 4,5 K
L-500 R 7,1 K
L-500 L 11,8 K
L-500XL 13,3 K

I'm guessing the 14,1K was for the alnico version of the XL

http://guitarsbyfender.yuku.com/topic/9254

Would be good if you could give us the dimentions of the bobbins.

[David Schwab]

Bobbins are 66.25mm X 15.15mm X 10.13mm high. The space for the wire is 6.39mm high. The blade is 1.6mm thick, 54.45mm long, and 18.85mm high at the center of the arch.

[eggman6]

Thanks for that

[kevinT]

Cool. Thanks.

This is what I was looking for.

You're right, that is a BIG magnet. Wonder if Shea can get a magnet like this.

[David Schwab]

Cool. Thanks.

This is what I was looking for.

You're right, that is a BIG magnet. Wonder if Shea can get a magnet like this.

I'm not sure if the real L-500 has such a large magnet, because there's supposed to be a PC board type of thing under the magnet, and that would never fit in this case. You can't open a real L-500. The patent shows a smaller magnet.

But the broken lawrence pickup I chipped apart had the same bobbins, but in black, a flat top blade, and an almost as large ceramic magnet. Just not quite as thick, but pretty big.

[kmensik]

500L anatomy

Hi all, especially David. I recently got one Bill Lawrence with one open coil. There is really no reasonable disassembly, so at least I tried to cut the base off. The plastic is very sturdy, chrome coating heavy duty. It uses shielded solid wires for the leads. Only the bottom is epoxied, not the whole coils.
Now you see four little ceramic magnets, separated from the blades with a grounded copper foil.

[eggman6]

If you wanted to completely disassemble the pickup you might be able to remove that epoxy with vinegar but apparently it takes a very long time.

Acetone works nicely but it wouldn't stop with the epoxy and would bugger up those bobbins if they are abs.

[kmensik]

Vinegar to remove set epoxy

Thanks for that vinegar tip. It works, softening the epoxy into a hard jelly, that can be cut off easily. But it takes about 1mm/day. I suppose vinegar will corrode the copper windings to death.
Does anyone have dead EMG to try it on their epoxy?

[David Schwab]

I just thought about this... every Lawrence pickup I've seen was encapsulated with polyester resin, not epoxy. You can tell by the styrene smell.

[eggman6]

No chance removing that then if thats the case, not without ruining the pickup.

[kmensik]

lawrence repair

After two weeks in vinegar, once a day scraping softened ressin off, I saved the coils and the magnets. Luckily the good coil was still OK, and I repaired the open coil. The demage was done on the outside windings. No wonder, there was only a little piece of tape, not covering all the coil surface against the pickup tub. The coils were not potted, only a little dirty with that ressin. The pickup was probably preassembled, coils glued together, the bottom taped with the copper foil, magnets glued, then some ressin was poured into the "pickup tub" and all the parts pressed in.
The bad thing is that the ressin swells in vinegar, and the pressure made one bobbin crack a little. But it is back, working again. The repair is not visible from the front.

[Ronsonic]

Good save. And Eggman, a great tip on the vinegar. Gonna keep that in my store of "one o' these days" tricks. Could come in very, very handy. Thanks.